This invention relates to dopamine receptors from mammalian species and the corresponding genes. In particular, it relates to the isolation, sequencing and/or cloning of D.sub.2 dopamine receptor genes, the synthesis of D.sub.2 dopamine receptors by transformed cells, and the manufacture and use of a variety of novel products enabled by the identification and cloning of DNA encoding dopamine receptors.
Dopamine receptors in general have been implicated in a large number of neurological and other disorders, including, for example, movement disorders, schizophrenia, drug addiction, Parkinson's disease, Tourette syndrome, Tardive Dyskinesia, and many others. As a result, the dopamine receptor has been the subject of numerous pharmacological and biochemical studies.
In general, dopamine receptors can be classified into D.sub.1 and D.sub.2 subtypes based on pharmacological and biochemical characteristics (1,2). The D.sub.2 dopamine receptor has been implicated in the pathophysiology and treatment of the mentioned disorders. In addition, it is known that the D.sub.2 dopamine receptor interacts with guanine nucleotide binding proteins to modulate second messenger systems (6,7).
Despite the heavy emphasis placed on elucidation of the existence and properties of the dopamine receptor and its gene, identification, isolation and cloning have been inaccessible heretofore. This is true despite the knowledge that other members of the family of receptors that are coupled to G proteins share a significant similarity in primary amino acid sequence and exhibit an archetypical topology predicted to consist of seven putative transmembrane domains (8). Regarding the serotonin receptor, e.g., see Julius et al., Science, Vol. 241, 558 (1988).